Weird Port numbers and phones unregistering

When I look at the connected peers, I see most have low port numbers (8000 and below) and most of them o=are on port 5060. No prblems here.

I see a handful of peers that are connected to weird high ports (39000+) and two of these ‘high-port’ telephones (polycoms on ports 49222 and 49230) keep getting unregistered after they receive a call.

Q1) Why do phones connect on such weird ports?

Q2) Is there a way to force them to use lower ports?

Q3) Why would they keep unregistering?

BTW, these are NAT’d telephones.

From what I remember the Polycom’s had an issue with NAT. Only the latest versions have less issues.

The “weird” high ports are the NAT router on the far end assigning random port numbers for the mapping. I have some NAT routers which will assign low, and some in the 50,000 range. Nothing to be concerned about.

The fact that they keep unregistering probably means that the NAT mapping is probably expiring between registration requests. I have had to shorten my re-reg timeout to 30 seconds on some phones behind NAT to ensure the router/firewall doesn’t flush state.